1. Technical Field
This invention relates in general to magnetic media tape and tape drives, and in particular to reducing the mechanical distortion created in the magnetic tape at the take-up reel interface.
2. Background Art
One type of magnetic media tape on single reel tape cartridges is typically threaded into and unthreaded from a tape drive with a leading portion such as a leader block or leader tape. Occasionally, these systems experience a mechanical embossment or distortion when they are loaded into the take-up reel. This problem is more frequent with thin, high capacity magnetic tapes. The distortion typically occurs near the interface between the drive hub and the leader portion wherever there is an unsupported region or gap (see FIGS. 1-4). Ideally, the outer edge of the leader portion is substantially flush with the outer diameter of the reel hub and centered in its throat. However, in the prior art, there is a misalignment range of approximately +/-100 microns.
As shown in FIGS. 1 and 2, a small but significant embossment 11, 13, respectively (shown exaggerated for ease of understanding), is formed in subsequent layers of the thin magnetic tape 15 wrapped around the hub 17 on top of the leader block 19 at a uniform tension. Embossments 11, 13 form on top of the edges of the leader block 19, and on top of the throat edges of hub 17, respectively.
A third type of discontinuity is shown in FIG. 3. Here, a larger than normal gap 12 is formed to one side of leader block 19 when it is not centered in the throat of hub 17. Gap 12 leads to the formation of an embossment 14 in tape 15. In FIG. 4, a reel 16 has a slit 18 for receiving a piece of leader tape 20 that is spliced to the end of magnetic tape 22 with a strip of adhesive tape 24. In this configuration, two discontinuities can be formed in magnetic tape 22: an embossment 26 at the throat of slit 18, and/or an embossment 28 at or near adhesive tape 24. Each of these discontinuities can result in recording errors in the tape where data is recorded. An improved method for reducing mechanical distortion in magnetic tape is needed.